5962-01-189-9484_技术文档

2-Terminal IC

Temperature Transducer

AD590

FEATURES

PIN CONFIGURATIONS

Linear current output: 1 μA/K

Wide temperature range: −55°C to +150°C

Probe-compatible ceramic sensor package

2-terminal device: voltage in/current out

Laser trimmed to 0.5°C calibration accuracy (AD590M)

Excellent linearity: 0.3°C over full range (AD590M)

Wide power supply range: 4 V to 30 V

Sensor isolation from case

NC

V+

V–

NC

1

2

3

4

8

7

6

5

NC

TOP VIEW

(Not to Scale)

NC = NO CONNECT

+

–

Low cost

Figure 1. 2-Lead CQFP

Figure 2. 8-Lead SOIC

–

GENERAL DESCRIPTION

The AD590 is a 2-terminal integrated circuit temperature

transducer that produces an output current proportional to

absolute temperature. For supply voltages between 4 V and

30 V, the device acts as a high impedance, constant current

regulator passing 1 μA/K. Laser trimming of the chip’s thin-film

resistors is used to calibrate the device to 298.2 μA output at

298.2 K (25°C).

+

Figure 3. 3-Pin TO-52

PRODUCT HIGHLIGHTS

The AD590 should be used in any temperature-sensing

application below 150°C in which conventional electrical

temperature sensors are currently employed. The inherent

low cost of a monolithic integrated circuit combined with the

elimination of support circuitry makes the AD590 an attractive

alternative for many temperature measurement situations.

Linearization circuitry, precision voltage amplifiers, resistance

measuring circuitry, and cold junction compensation are not

needed in applying the AD590.

1. The AD590 is a calibrated, 2-terminal temperature sensor

requiring only a dc voltage supply (4 V to 30 V). Costly

transmitters, filters, lead wire compensation, and linearization

circuits are all unnecessary in applying the device.

2. State-of-the-art laser trimming at the wafer level in

conjunction with extensive final testing ensures that

AD590 units are easily interchangeable.

In addition to temperature measurement, applications include

temperature compensation or correction of discrete components,

biasing proportional to absolute temperature, flow rate

measurement, level detection of fluids and anemometry.

The AD590 is available in chip form, making it suitable for

hybrid circuits and fast temperature measurements in

protected environments.

3. Superior interface rejection occurs because the output is a

current rather than a voltage. In addition, power

requirements are low (1.5 mW @ 5 V @ 25°C). These

features make the AD590 easy to apply as a remote sensor.

4. The high output impedance (>10 MΩ) provides excellent

rejection of supply voltage drift and ripple. For instance,

changing the power supply from 5 V to 10 V results in only

a 1 μA maximum current change, or 1°C equivalent error.

The AD590 is particularly useful in remote sensing applications.

The device is insensitive to voltage drops over long lines due to

its high impedance current output. Any well-insulated twisted

pair is sufficient for operation at hundreds of feet from the

receiving circuitry. The output characteristics also make the

AD590 easy to multiplex: the current can be switched by a

CMOS multiplexer, or the supply voltage can be switched by a

logic gate output.

5. The AD590 is electrically durable: it withstands a forward

voltage of up to 44 V and a reverse voltage of 20 V.

Therefore, supply irregularities or pin reversal does not

damage the device.

Rev. D

Information furnished by Analog Devices is believed to be accurate and reliable. However, no

responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other

rights of third parties that may result from its use. Specifications subject to change without notice. No

license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

Trademarks and registeredtrademarks arethe property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781.329.4700

Fax: 781.461.3113

www.analog.com

AD590

TABLE OF CONTENTS

Features .............................................................................................. 1

Explanation of Temperature Sensor Specifications ..................7

Calibration Error...........................................................................7

General Description......................................................................... 1

Pin Configurations ........................................................................... 1

Product Highlights ........................................................................... 1

Revision History ............................................................................... 2

Specifications..................................................................................... 3

AD590J and AD590K Specifications ......................................... 3

AD590L and AD590M Specifications ....................................... 4

Absolute Maximum Ratings............................................................ 5

ESD Caution.................................................................................. 5

General Description......................................................................... 6

Circuit Description....................................................................... 6

Error vs. Temperature: with Calibration Error Trimmed

Out...................................................................................................7

Error vs. Temperature: No User Trims.......................................7

Nonlinearity ...................................................................................7

Voltage and Thermal Environment Effects ...............................8

General Applications...................................................................... 10

Outline Dimensions....................................................................... 13

Ordering Guide .......................................................................... 14

REVISION HISTORY

1/06—Rev. C to Rev. D

Updated Format..................................................................Universal

Changes to Figure 4 Equation......................................................... 4

9/03—Rev. B to Rev. C

Added SOIC-8 Package......................................................Universal

Change to Figure 1 ........................................................................... 1

Updated Outline Dimensions....................................................... 13

Added Ordering Guide.................................................................. 14

Rev. D | Page 2 of 16

AD590

SPECIFICATIONS

AD590J AND AD590K SPECIFICATIONS

25°C and V_S= 5 V, unless otherwise noted.¹

Table 1.

AD590J

Typ

AD590K

Typ

Parameter

Min

4

Max

Min

4

Max

Unit

POWER SUPPLY

Operating Voltage Range

OUTPUT

30

V

Nominal Current Output @ 25°C (298.2K)

Nominal Temperature Coefficient

Calibration Error @ 25°C

Absolute Error (Over Rated Performance Temperature Range)

Without External Calibration Adjustment

With 25°C Calibration Error Set to Zero

Nonlinearity

298.2

1

298.2

1

μA

μA/K

°C

5.0

2.5

°C

10

3.0

5.5

2.0

For TO-52 and CQFP Packages

For 8-Lead SOIC Package

Repeatability²

°C

1.5

0.1

0.8

1.0

0.1

Long-Term Drift³

Current Noise

40

pA/√Hz

Power Supply Rejection

4 V ≤ V_S≤ 5 V

5 V ≤ V_S≤ 15 V

0.5

0.2

0.1

10¹⁰

100

20

0.5

0.2

0.1

10¹⁰

100

20

μA/V

μV/V

μA/V

Ω

pF

μs

15 V ≤ V_S≤ 30 V

Case Isolation to Either Lead

Effective Shunt Capacitance

Electrical Turn-On Time

Reverse Bias Leakage Current (Reverse Voltage = 10 V)⁴

10

pA

¹Specifications shown in boldface are tested on all production units at final electrical test. Results from those tests are used to calculate outgoing quality levels. All

minimum and maximum specifications are guaranteed, although only those shown in boldface are tested on all production units.

²Maximum deviation between +25°C readings after temperature cycling between −55°C and +150°C; guaranteed, not tested.

³Conditions: constant 5 V, constant 125°C; guaranteed, not tested.

⁴Leakage current doubles every 10°C.

Rev. D | Page 3 of 16

AD590

AD590L AND AD590M SPECIFICATIONS

25°C and V_S= 5 V, unless otherwise noted.¹

Table 2.

AD590L

Typ

AD590M

Typ

Parameter

Min

Max

Min

Max

Unit

POWER SUPPLY

Operating Voltage Range

OUTPUT

4

30

4

30

V

Nominal Current Output @ 25°C (298.2K)

Nominal Temperature Coefficient

Calibration Error @ 25°C

Absolute Error (Over Rated Performance Temperature Range)

Without External Calibration Adjustment

With 25°C Calibration Error Set to Zero

Nonlinearity

298.2

1

298.2

1

μA

μA/K

°C

1.0

0.5

3.0

1.6

0.4

0.1

1.ꢀ

1.0

0.3

0.1

Repeatability²

Long-Term Drift³

Current Noise

40

pA/√Hz

Power Supply Rejection

4 V ≤ V_S≤ 5 V

5 V ≤ V_S≤ 15 V

0.5

0.2

0.1

10¹⁰

100

20

0.5

0.2

0.1

10¹⁰

100

20

μA/V

Ω

pF

μs

15 V ≤ V_S≤ 30 V

Case Isolation to Either Lead

Effective Shunt Capacitance

Electrical Turn-On Time

Reverse Bias Leakage Current (Reverse Voltage = 10 V)⁴

10

pA

¹Specifications shown in boldface are tested on all production units at final electrical test. Results from those tests are used to calculate outgoing quality levels. All

minimum and maximum specifications are guaranteed, although only those shown in boldface are tested on all production units.

²Maximum deviation between +25°C readings after temperature cycling between –55°C and +150°C; guaranteed, not tested.

³Conditions: constant 5 V, constant 125°C; guaranteed, not tested.

⁴Leakage current doubles every 10°C.

°K

°C

+223°

–50°

+273° +298° +323°

0° +25° +50°

+373°

+100°

+423°

+150°

°F –100°

0°

+100°

+32° +70°

+200°

+212°

+300°

5

9

o

^oC =

(

^oF − 32

K = C + 273.15

)

9

5

⎛

⎝

⎞

⎠

o

^oF =

^oC + 32 ^oR = F + 459.7

⎜

⎟

Figure 4. Temperature Scale Conversion Equations

Rev. D | Page 4 of 16

AD590

ABSOLUTE MAXIMUM RATINGS

Table 3.

Stresses above those listed under Absolute Maximum Ratings

Parameter

Rating

may cause permanent damage to the device. This is a stress

rating only and functional operation of the device at these or

any other conditions above those indicated in the operational

section of this specification is not implied. Exposure to absolute

maximum rating conditions for extended periods may affect

device reliability.

Forward Voltage ( E+ or E–)

Reverse Voltage (E+ to E–)

Breakdown Voltage (Case E+ or E–)

Rated Performance Temperature Range¹

Storage Temperature Range¹

Lead Temperature (Soldering, 10 sec)

44 V

−20 V

200 V

−55°C to +150°C

−65°C to +155°C

300°C

¹The AD590 was used at −100°C and +200°C for short periods of

measurement with no physical damage to the device. However, the absolute

errors specified apply to only the rated performance temperature range.

ESD CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on

the human body and test equipment and can discharge without detection. Although this product features

proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy

electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance

degradation or loss of functionality.

Rev. D | Page 5 of 16

AD590

GENERAL DESCRIPTION

PTAT current. Figure 6 is the schematic diagram of the AD590.

In this figure, Q8 and Q11 are the transistors that produce the

PTAT voltage. R5 and R6 convert the voltage to current. Q10,

whose collector current tracks the collector currents in Q9 and

Q11, supplies all the bias and substrate leakage current for the

rest of the circuit, forcing the total current to be PTAT. R5 and

R6 are laser-trimmed on the wafer to calibrate the device at 25°C.

The AD590H has 60 μ inches of gold plating on its Kovar leads

and Kovar header. A resistance welder is used to seal the nickel

cap to the header. The AD590 chip is eutectically mounted to

the header and ultrasonically bonded to with 1 mil aluminum

wire. Kovar composition: 53% iron nominal; 29% 1% nickel;

17% 1% cobalt; 0.65% manganese max; 0.20% silicon max;

0.10% aluminum max; 0.10% magnesium max; 0.10% zirconium

max; 0.10% titanium max; and 0.06% carbon max.

Figure 7 shows the typical V–I characteristic of the circuit at

25°C and the temperature extremes.

The AD590F is a ceramic package with gold plating on its

Kovar leads, Kovar lid, and chip cavity. Solder of 80/20 Au/Sn

composition is used for the 1.5 mil thick solder ring under the

lid. The chip cavity has a nickel underlay between the metallization

and the gold plating. The AD590 chip is eutectically mounted in

the chip cavity at 410°C and ultrasonically bonded to with 1 mil

aluminum wire. Note that the chip is in direct contact with the

ceramic base, not the metal lid. When using the AD590 in die

form, the chip substrate must be kept electrically isolated

(floating) for correct circuit operation.

+

R1

R2

260Ω 1040Ω

Q2

Q5

Q3

C1

Q1

Q4

Q6

26pF

Q12

Q8

Q7

R4

11kΩ

CHIP

SUBSTRATE

R3

5kΩ

66MILS

Q9

Q10

Q11

1

V+

8

1

R5

146Ω

R6

820Ω

–

Figure 6. Schematic Diagram

42MILS

V–

+150°C

423

THE AD590 IS AVAILABLE IN LASER-TRIMMED CHIP FORM;

CONSULT THE CHIP CATALOG FOR DETAILS

+25°C

–55°C

298

218

Figure 5. Metallization Diagram

CIRCUIT DESCRIPTION¹

The AD590 uses a fundamental property of the silicon

transistors from which it is made to realize its temperature

proportional characteristic: if two identical transistors are

operated at a constant ratio of collector current densities, r,

then the difference in their base-emitter voltage is (kT/q)(In r).

Because both k (Boltzman’s constant) and q (the charge of an

electron) are constant, the resulting voltage is directly

proportional to absolute temperature (PTAT).

0

1

2

3

4

5

6

30

SUPPLY VOLTAGE (V)

Figure 7. V–I Plot

¹For a more detailed description, see M.P. Timko, “A Two-Terminal IC

Temperature Transducer,” IEEE J. Solid State Circuits, Vol. SC-11, p. ꢀ84-ꢀ88,

Dec. 19ꢀ6. Understanding the Specifications–AD590.

In the AD590, this PTAT voltage is converted to a PTAT current

by low temperature coefficient thin-film resistors. The total

current of the device is then forced to be a multiple of this

Rev. D | Page 6 of 16

AD590

+

5V

+

–

EXPLANATION OF TEMPERATURE SENSOR

SPECIFICATIONS

AD590

+

The way in which the AD590 is specified makes it easy to apply

it in a wide variety of applications. It is important to understand

the meaning of the various specifications and the effects of the

supply voltage and thermal environment on accuracy.

R

100Ω

V

= 1mV/K

–

T

950Ω

–

Figure 9. One Temperature Trim

The AD590 is a PTAT¹current regulator. That is, the output

current is equal to a scale factor times the temperature of the

sensor in degrees Kelvin. This scale factor is trimmed to 1 μA/K

at the factory, by adjusting the indicated temperature (that is,

the output current) to agree with the actual temperature. This is

done with 5 V across the device at a temperature within a few

degrees of 25°C (298.2K). The device is then packaged and

tested for accuracy over temperature.

ERROR VS. TEMPERATURE: WITH CALIBRATION

ERROR TRIMMED OUT

Each AD590 is tested for error over the temperature range with

the calibration error trimmed out. This specification could also

be called the variance from PTAT, because it is the maximum

difference between the actual current over temperature and a

PTAT multiplication of the actual current at 25°C. This error

consists of a slope error and some curvature, mostly at the

temperature extremes. Figure 10 shows a typical AD590K

temperature curve before and after calibration error trimming.

CALIBRATION ERROR

At final factory test, the difference between the indicated

temperature and the actual temperature is called the calibration

error. Since this is a scale factory error, its contribution to the

total error of the device is PTAT. For example, the effect of the

1°C specified maximum error of the AD590L varies from 0.73°C at

–55°C to 1.42°C at 150°C. Figure 8 shows how an exaggerated

calibration error would vary from the ideal over temperature.

2

BEFORE

CALIBRATION

TRIM

CALIBRATION

ERROR

0

ACTUAL

TRANSFER

FUNCTION

AFTER

CALIBRATION

TRIM

I

ACTUAL

IDEAL

TRANSFER

FUNCTION

CALIBRATION

ERROR

–2

–55

150

298.2

TEMPERATURE (°C)

Figure 10. Effect to Scale Factor Trim on Accuracy

ERROR VS. TEMPERATURE: NO USER TRIMS

Using the AD590 by simply measuring the current, the total

error is the variance from PTAT, described above, plus the effect

of the calibration error over temperature. For example, the

AD590L maximum total error varies from 2.33°C at –55°C to

3.02°C at 150°C. For simplicity, only the large figure is shown

on the specification page.

298.2

TEMPERATURE (°K)

Figure 8. Calibration Error vs. Temperature

The calibration error is a primary contributor to the maximum

total error in all AD590 grades. However, because it is a scale

factor error, it is particularly easy to trim. Figure 9 shows the

most elementary way of accomplishing this. To trim this circuit,

the temperature of the AD590 is measured by a reference

temperature sensor and R is trimmed so that V_T= 1 mV/K at

that temperature. Note that when this error is trimmed out at

one temperature, its effect is zero over the entire temperature

range. In most applications, there is a current-to-voltage

conversion resistor (or, as with a current input ADC, a

NONLINEARITY

Nonlinearity as it applies to the AD590 is the maximum

deviation of current over temperature from a best-fit straight

line. The nonlinearity of the AD590 over the −55°C to +150°C

range is superior to all conventional electrical temperature

sensors such as thermocouples, RTDs, and thermistors. Figure 11

shows the nonlinearity of the typical AD590K from Figure 10.

reference) that can be trimmed for scale factor adjustment.

¹T(°C) = T(K) − 2ꢀ3.2. Zero on the Kelvin scale is absolute zero; there is no

lower temperature.

Rev. D | Page ꢀ of 16

AD590

VOLTAGE AND THERMAL ENVIRONMENT EFFECTS

1.6

The power supply rejection specifications show the maximum

expected change in output current vs. input voltage changes.

The insensitivity of the output to input voltage allows the use of

unregulated supplies. It also means that hundreds of ohms of

resistance (such as a CMOS multiplexer) can be tolerated in

series with the device.

0.8

0.8°C MAX

0

0.8°C

MAX

0.8°C

MAX

It is important to note that using a supply voltage other than 5 V

does not change the PTAT nature of the AD590. In other words,

this change is equivalent to a calibration error and can be

removed by the scale factor trim (see Figure 10).

–0.8

–1.6

–55

150

TEMPERATURE (°C)

The AD590 specifications are guaranteed for use in a low

thermal resistance environment with 5 V across the sensor.

Large changes in the thermal resistance of the sensor’s environment

change the amount of self-heating and result in changes in the

output, which are predictable but not necessarily desirable.

Figure 11. Nonlinearity

Figure 12 shows a circuit in which the nonlinearity is the major

contributor to error over temperature. The circuit is trimmed

by adjusting R1 for a 0 V output with the AD590 at 0°C. R2 is

then adjusted for 10 V output with the sensor at 100°C. Other

pairs of temperatures can be used with this procedure as long as

they are measured accurately by a reference sensor. Note that

for 15 V output (150°C), the V+ of the op amp must be greater

than 17 V. Also, note that V− should be at least −4 V; if V− is

ground, there is no voltage applied across the device.

The thermal environment in which the AD590 is used

determines two important characteristics: the effect of self-

heating and the response of the sensor with time. Figure 14 is a

model of the AD590 that demonstrates these characteristics.

T

θ

T

θ

CA

J

JC

C

+

–

15V

P

T

A

C

CH

R1

R2

2kΩ

5kΩ

35.7kΩ

27kΩ

97.6kΩ

AD581

Figure 14. Thermal Circuit Model

30pF

As an example, for the TO-52 package, θ_JCis the thermal

resistance between the chip and the case, about 26°C/W. θ_CAis

the thermal resistance between the case and the surroundings

and is determined by the characteristics of the thermal

connection. Power source P represents the power dissipated

on the chip. The rise of the junction temperature, T_J, above the

ambient temperature, T_A, is

100mV/°C

= 100mV/°C

AD707A

V

T

AD590

V–

Figure 12. 2-Temperature Trim

T_J− T_A= P(θ_JC+ θ_CA)

(1)

2

0

Table 4 gives the sum of θ_JCand θ_CAfor several common

thermal media for both the H and F packages. The heat sink

used was a common clip-on. Using Equation 1, the temperature

rise of an AD590 H package in a stirred bath at 25°C, when

driven with a 5 V supply, is 0.06°C. However, for the same

conditions in still air, the temperature rise is 0.72°C. For a given

supply voltage, the temperature rise varies with the current and

is PTAT. Therefore, if an application circuit is trimmed with the

sensor in the same thermal environment in which it is used, the

scale factor trim compensates for this effect over the entire

temperature range.

–2

–55

0

100

150

TEMPERATURE (°C)

Figure 13. Typical 2-Trim Accuracy

Rev. D | Page 8 of 16

AD590

Table 4. Thermal Resistance

θ

_JC+ θ_CA

(°C/Watt)

τ (sec)¹

F

T

FINAL

Medium

H

F

H

Aluminum Block

Stirred Oil²

Moving Air³

30

42

10

60

0.6

1.4

0.1

0.6

With Heat Sink

Without Heat Sink

Still Air

45

115

–

190

5.0

13.5

–

10.0

–t/τ

)

T(t) = T

+ (T

– T ) × (1 – e

INITIAL

FINAL

With Heat Sink

Without Heat Sink

191

480

–

650

108

60

–

30

¹τ is dependent upon velocity of oil; average of several velocities listed above.

²Air velocity @ 9 ft/sec.

T

INITIAL

τ

4τ

TIME

³The time constant is defined as the time required to reach 63.2% of an

instantaneous temperature change.

Figure 15. Time Response Curve

The time response of the AD590 to a step change in

temperature is determined by the thermal resistances and the

thermal capacities of the chip, C_CH, and the case, C_C. C_CHis

about 0.04 Ws/°C for the AD590. C_Cvaries with the measured

medium, because it includes anything that is in direct thermal

contact with the case. The single time constant exponential

curve of Figure 15 is usually sufficient to describe the time

response, T (t). Table 4 shows the effective time constant, τ, for

several media.

Rev. D | Page 9 of 16

AD590

GENERAL APPLICATIONS

V+

Figure 16 demonstrates the use of a low cost digital panel meter

for the display of temperature on either the Kelvin, Celsius, or

Fahrenheit scales. For Kelvin temperature, Pin 9, Pin 4, and

Pin 2 are grounded; for Fahrenheit temperature, Pin 4 and Pin 2

are left open.

R3

10kΩ

+

–

AD590L

#2

–

AD707A

+

–

R1

5MΩ

AD590L

#1

5V

(T1 – T2) × (10mV/°C)

+

R2

50kΩ

R4

10kΩ

OFFSET

8

9

4

2

CALIBRATION

6

5

+

–

V–

GAIN

SCALING

AD590

AD2040

3

Figure 18. Differential Measurements

OFFSET

SCALING

Figure 19 is an example of a cold junction compensation circuit

for a Type J thermocouple using the AD590 to monitor the

reference junction temperature. This circuit replaces an ice-bath

as the thermocouple reference for ambient temperatures

between 15°C and 35°C. The circuit is calibrated by adjusting R_T

for a proper meter reading with the measuring junction at a

known reference temperature and the circuit near 25°C. Using

components with the TCs as specified in Figure 19, compensation

accuracy is within 0.5°C for circuit temperatures between

15°C and 35°C. Other thermocouple types can be accommodated

with different resistor values. Note that the TCs of the voltage

reference and the resistors are the primary contributors to error.

GND

Figure 16. Variable Scale Display

The above configuration yields a 3-digit display with 1°C or 1°F

resolution, in addition to an absolute accuracy of 2.0°C over

the −55°C to +125°C temperature range, if a one-temperature

calibration is performed on an AD590K, AD590L, or AD590M.

Connecting several AD590 units in series, as shown in Figure 17,

allows the minimum of all the sensed temperatures to be

indicated. In contrast, using the sensors in parallel yields the

average of the sensed temperatures.

7.5V

15V

+

IRON

REFERENCE

JUNCTION

AD590

–

5V

+

CONSTANTAN

+

AD590

+

–

+

–

+

–

AD590

–

AD590

–

+

–

+

AD590

–

AD580

C

+

–

U

52.3Ω

MEASURING

JUNCTION

+

10kΩ

(0.1%)

333.3Ω

(0.1%)

V

OUT

V

MIN

V AVG

T

+

–

T

8.66kΩ

–

METER

R

T

Figure 17. Series and Parallel Connection

1kΩ

RESISTORS ARE 1%, 50ppm/°C

The circuit in Figure 18 demonstrates one method by which

differential temperature measurements can be made. R1 and R2

can be used to trim the output of the op amp to indicate a

desired temperature difference. For example, the inherent offset

between the two devices can be trimmed in. If V+ and V− are

radically different, then the difference in internal dissipation

causes a differential internal temperature rise. This effect can be

used to measure the ambient thermal resistance seen by the

sensors in applications such as fluid-level detectors or anemometry.

Figure 19. Cold Junction Compensation Circuit for Type J Thermocouple

Rev. D | Page 10 of 16

AD590

20pF

Figure 20 is an example of a current transmitter designed to be

used with 40 V, 1 kΩ systems; it uses its full current range of 4

to 20 mA for a narrow span of measured temperatures. In this

example, the 1 μA/K output of the AD590 is amplified to

1 mA/°C and offset so that 4 mA is equivalent to 17°C and

20 mA is equivalent to 33°C. R_Tis trimmed for proper reading

at an intermediate reference temperature. With a suitable choice

of resistors, any temperature range within the operating limits

of the AD590 can be chosen.

1.25kΩ

REF

+5V

–15V

MC

1408/1508

DAC OUT

1.15kΩ

BIT 1

BIT 2

BIT 3

BIT 4

BIT 8

BIT 7

BIT 6

BIT 5

200Ω, 15T

+5V

+2.5V

AD580

V+

200Ω

+

–

AD581

4mA = 17°C

12mA = 25°C

20mA = 33°C

+5V

6.98kΩ

1kΩ, 15T

+

V

OUT

1kΩ

OUTPUT HIGH-

35.7kΩ

3

2

8

TEMPERATURE ABOVE SETPOINT

30pF

7

R

T

+

LM311

–

5kΩ

OUTPUT LOW-

TEMPERATURE BELOW SETPOINT

AD590

1

–

4

AD707A

–

5.1MΩ

–15V

+

5kΩ

500Ω

12.7kΩ

10Ω

6.8kΩ

0.01µF

10kΩ

Figure 22. DAC Setpoint

The voltage compliance and the reverse blocking characteristic

of the AD590 allow it to be powered directly from 5 V CMOS

logic. This permits easy multiplexing, switching, or pulsing for

minimum internal heat dissipation. In Figure 23, any AD590

connected to a logic high passes a signal current through the

current measuring circuitry, while those connected to a logic

zero pass insignificant current. The outputs used to drive the

AD590s can be employed for other purposes, but the additional

capacitance due to the AD590 should be taken into account.

V–

Figure 20. 4 to 20 mA Current Transmitter

Figure 21 is an example of a variable temperature control circuit

(thermostat) using the AD590. R_Hand R_Lare selected to set the

high and low limits for R_SET. R_SETcould be a simple pot, a

calibrated multiturn pot, or a switched resistive divider. Powering

the AD590 from the 10 V reference isolates the AD590 from

supply variations while maintaining a reasonable voltage (~7 V)

across it. Capacitor C1 is often needed to filter extraneous noise

from remote sensors. R_Bis determined by the β of the power

transistor and the current requirements of the load.

5V

V+

+

AD581

V+

AD590

OUT

10V

–

CMOS

GATES

+

–

HEATING

ELEMENTS

V–

+

–

R

B

R

H

AD590

+

–

7

LM311

4

2

3

–

+

R

SET

+

–

1

R

L

C1

1kΩ (0.1%)

10kΩ

GND

Figure 21. Simple Temperature Control Circuit

Figure 23. AD590 Driven from CMOS Logic

Figure 22 shows that the AD590 can be configured with an 8-bit

DAC to produce a digitally controlled setpoint. This particular

circuit operates from 0°C (all inputs high) to 51.0°C (all inputs

low) in 0.2°C steps. The comparator is shown with 1.0°C

hysteresis, which is usually necessary to guard-band for extraneous

noise. Omitting the 5.1 MΩ resistor results in no hysteresis.

Rev. D | Page 11 of 16

AD590

CMOS analog multiplexers can also be used to switch AD590

current. Due to the AD590’s current mode, the resistance of

such switches is unimportant as long as 4 V is maintained

across the transducer. Figure 24 shows a circuit that combines

the principle demonstrated in Figure 23 with an 8-channel

CMOS multiplexer. The resulting circuit can select 1 to 80

sensors over only 18 wires with a 7-bit binary word.

The inhibit input on the multiplexer turns all sensors off for

minimum dissipation while idling.

Figure 25 demonstrates a method of multiplexing the AD590 in

the 2-trim mode (see Figure 12 and Figure 13). Additional AD590s

and their associated resistors can be added to multiplex up to

eight channels of 0.5°C absolute accuracy over the temperature

range of −55°C to +125°C. The high temperature restriction of

125°C is due to the output range of the op amps; output to

150°C can be achieved by using a 20 V supply for the op amp.

10V

0

1

2

16

3

14

2

4028

CMOS

+

–

+

–

+

–

+

–

+

–

+

–

AD590

00

BCD-TO-

DECIMAL

DECODER

+

–

+

–

+

–

02

01

12

11

10

11

12

13

10

22

21

20

ROW

SELECT

8

10V

16

2

1

0

15 14 13

9

LOGIC

LEVEL

INTERFACE

4051 CMOS ANALOG

MULTIPLEXER

10

COLUMN

SELECT

11

6

INHIBIT

BINARY TO 1-OF-8 DECODER

7

8

10kΩ 10mV/°C

Figure 24. Matrix Multiplexer

2kΩ

5kΩ

35.7kΩ

97.6kΩ

+15V

5kΩ

+

–

97.6kΩ

AD581

V

OUT

V+

S1

S2

AD707A

10mV/°C

DECODER/

DRIVER

–15V

27kΩ

S8

AD7501

+15V

–15V

TTL/DTL TO CMOS

INTERFACE

+

–

+

EN

BINARY

CHANNEL

SELECT

AD590L

–

–5V TO –15V

Figure 25. 8-Channel Multiplexer

Rev. D | Page 12 of 16

AD590

OUTLINE DIMENSIONS

0.030 (0.76)

TYP

POSITIVE LEAD

INDICATOR

0.019 (0.48)

0.017 (0.43)

0.015 (0.38)

0.500 (12.70)

MIN

0.150 (3.81)

0.115 (2.92)

0.250 (6.35) MIN

0.050 (1.27) MAX

0.050 (1.27) T.P.

0.093 (2.36)

0.081 (2.06)

0.055 (1.40)

0.050 (1.27)

0.045 (1.14)

0.048 (1.22)

0.028 (0.71)

3

0.100

(2.54)

T.P.

2

0.500 (12.69)

MIN

0.210 (5.34)

0.200 (5.08)

0.190 (4.83)

0.046 (1.17)

0.036 (0.91)

1

0.050

(1.27)

T.P.

0.240 (6.10)

0.230 (5.84)

0.220 (5.59)

0.019 (0.48)

0.016 (0.41)

0.0065 (0.17)

0.0050 (0.13)

0.0045 (0.12)

0.030 (0.76) MAX

45° T.P.

0.050 (1.27)

0.041 (1.04)

0.021 (0.53) MAX

BASE & SEATING PLANE

CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS

(IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR

REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.

0.015 (0.38)

TYP

Figure 26. 2-Lead Ceramic Flat Package [CQFP]

(F-2)

Dimensions shown in inches and (millimeters)

Figure 27. 3-Pin Metal Header Package [TO-52]

(H-03)

Dimensions shown in inches and (millimeters)

5.00 (0.1968)

4.80 (0.1890)

8

1

5

4

6.20 (0.2440)

5.80 (0.2284)

4.00 (0.1574)

3.80 (0.1497)

1.27 (0.0500)

BSC

0.50 (0.0196)

× 45°

1.75 (0.0688)

1.35 (0.0532)

0.25 (0.0099)

0.25 (0.0098)

0.10 (0.0040)

8°

0.51 (0.0201)

0.31 (0.0122)

0° 1.27 (0.0500)

COPLANARITY

0.10

0.25 (0.0098)

0.17 (0.0067)

SEATING

PLANE

0.40 (0.0157)

COMPLIANT TO JEDEC STANDARDS MS-012-AA

CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS

(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR

REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.

Figure 28. 8-Lead Standard Small Outline Package [SOIC]

Narrow Body

(R-8)

Dimensions shown in millimeters and (inches)

Rev. D | Page 13 of 16

AD590

ORDERING GUIDE

Model

Temperature Range

−55°C to +150°C

Package Description

2-Lead CQFP

3-Pin TO-52

8-Lead SOIC

2-Lead CQFP

3-Pin TO-52

8-Lead SOIC

2-Lead CQFP

3-Pin TO-52

2-Lead CQFP

3-Pin TO-52

Package Option

AD590JF¹

F-2

H-03

R-8

F-2

H-03

R-8

F-2

H-03

F-2

AD590JH¹

AD590JR

AD590JR-REEL

AD590JRZ²

AD590JRZ-RL²

AD590KF¹

AD590KH¹

AD590KR

AD590KR-REEL

AD590KRZ²

AD590KRZ-RL²

AD590LF¹

AD590LH¹

AD590MF¹

AD590MH¹

H-03

AD590JCHIPS

¹Available in 883B; consult sales for data sheet.

²Z = Pb-free part.

Rev. D | Page 14 of 16

AD590

NOTES

Rev. D | Page 15 of 16

AD590

NOTES

registered trademarks are the property of their respective owners.

C00533-0-1/06(D)

Rev. D | Page 16 of 16


型号：	5962-01-189-9484
厂家：	ADI
描述：	IC IC,TEMPERATURE SENSOR,BIPOLAR/JFET,FP,2PIN,CERAMIC, Analog IC:Other
文件：	总16页 (文件大小：387K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

5962-01-189-9484 [ADI]

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